Could Hurricane Irene Uproot the 9/11 Memorial?

With Hurricane Irene (maybe, possibly, fingers-crossed-it-won’t) headed straight for New York City, almost every precaution is being taken. People are stocking up on supplies like pet raincoats and booze, the M.T.A. is on lockdown and construction sites across the city are closed, with contractors directed to remove or secure everything that could potentially become a projectile in the event of high winds. This includes the biggest construction site in the city, the World Trade Center.

The timing could not be worse, as the hurricane could hit Sunday, exactly two weeks before the 9/11 Memorial is set to open.

But just how bad could a hurricane be for the memorial? The Observer got a tour of the site a week ago, and surrounding the two giant fountains are hundreds of feshly planted trees surrounded by itty, bitty cobblestones. What kind of impact would a Category 2 hurricane have on them?

The mayor said today that whatever happens, the memorial would still open on Sept. 11. “Currently, 13 of the 24 tower cranes active in are city are located at the World Trade Center site,” he said, an interesting fact that until this point The Observer had no idea about. “For those that want to know, this work stoppage will not have any effect on the scheduled opening of the 9/11 Memorial in time for the 10th anniversary of that tragic day. Since Wednesday, inspectors have been inspecting construction sites across the city to ensure equipment is properly secured.”

That is all well and good, but what kind of memorial would we be coming home to?

Secure those saplings! (WTC Progress)

“It’s never good to have a hurricane two weeks before opening,” Matthew Donham told The Observer. Mr. Donham is the project manager at PWP Landscape Architecture, the firm that helped design the memorial plaza with architect Michael Arad. The firm is credited with humanizing his spare project largely through the addition of hundreds of trees that will dot the plaza, more than half of which have already been planted in anticipation of the memorial’s opening.

This is thanks to a number of factors. For starters, PWP is using slow-growing, hardy Swamp White Oak trees, which have been growing in a nursery in New Jersey for five years now. The trees were also pruned on Wednesday, to give them an even look in preparation for the opening, but this also had the unintended effect of reducing the amount of foliage in proportion to the trunk and roots.

“We’ve taken a tree that has grown a structure to support a canopy larger than we have now because we’ve taken out a whole bunch of that canopy,” Mr. Donham said.

The trees also have larger “root balls” than are typical for a street or box planting, and those have been bolted to the plaza, further strengthening them. And because the trees were planted five years ago, they are far from saplings. As for the cobblestones, Mr. Donham said they are too heavy and too closely laid to be blown away. The biggest issue could be the freshly laid sod, which was actually stapled down in an effort to secure it.

So much for that new sod. (WTC Progress)

Ultimately, it all depends on how strong the storm is. “They’re the right tree for the area, which helps, but the thing about a hurricane is, it comes through and it just denudes everything,” Mr. Donham said. “In the tropics sometimes, a hurricane just comes through and it takes every tree. At a certain point, if the storm is big enough, there’s nothing you can do. I suppose you could make the argument, ‘well, don’t plant trees,’ but I don’t think that’s the right response. I’ve been reading the news, and it’s hard to know what’s coming.”

Michael Frazier, a spokesman for the 9/11 Memorial, said all possible precautions have been taken. “The memorial plaza has been cleared of all loose material and equipment,” he said, including construction fencing, extra material and tools. “Everything else has been secured and tied down. We have an emergency generator for powering pumps that’s on standby, in case there’s some flooding.” The site is located in the first-to-flood Zone A.

Short of total devastation, there should be time to replace any damaged trees or sod with spares from the nursery. “There could be quite a lot of clean-up to do next week,” Mr. Donham said.